Vehicle wheel compensating suspension



Sept. 30, 1952 l A. RoNNlNG A 2,612,387

VEHICLE WHEEL. COMPENSATING SUSPENSION Filed. June 22, 1945 7 Sheets-Sheel'l l I I7 E 41 E M' 47 4| f 4228 4s 46 A) c, 22 f 23 le* E A e, 3o 59 l la 57 28 43 44l B 4,3 sa 3 l il; 4s s1 @0 28 I I I l l 1` E.. v 53 i 5g 57 \A 44 Z9 l y o u f6 l 47?8 l ,8p 47 E le I8/ A F' l E.. l

``IE- E gmc/WM Anon Rowmawww Sept. 30, 1952 v A. RONNING 2,612,387

VEHICLE WHEEL COMPENSATING ASUSPENSION Filed June 22, 1945 ,'7 Sheets-Sheet 2 @2m NH Anoum Ronmng Sept. 30, 1952 A. RONNING VEHICLE WHEEL COMPENSATING SUSPENSION 7' sheets-sheet s Filed June 22, 1945 AooLP'H komm@ Sept. 30, 1952 A. RONNING VEHICLE WHEEL coMPENsATrNG SUSPENSION '7 Sheets-Sheet 4 Filed June 22, 1945 IF" IIE-.1 7

FLE

Sept. 30, 1952 A. RONNING VEHICLE WHEEL COMPENSATING SUSPENSION 7 Sheets-Sheet 5 Filed June 22, 1945 AooLPH Kommun:

A. RONNING VEHICLE WHEEL COMPENSATING SUSPENSION Sept. 3o, 1952 7 Sheets-Sheet 6 Filed June 22, 1945 AooLPH RoNmNcz Sept. 30, 1952 A. RONNING VEHICLE WHEEL COMPENSATING SUSPENSION '7 Sheets-Sheet 7 Filed June 22, 1945 AooLPH Romulus @2M M b/7&1

www

Patented Sept. 30, 1952 VEHICLE WHEEL COMPENSATING SUSPENSION Adolph Benning', Minneapolis, Minn. Applicationiune 22, 1945, serial No. 001,030 36 claims. (c1. 280-1045) This invention relates generally to improvements in vehicles of the heavy duty and high speed type, andthe primary object of the invention is to provide improvedv wheel suspension and support mechanisms for all vehicles using dual or tandem wheels. Another object is to provide a heavy Aduty vehicle supporting truck of novel and advantageous construction embodying a plurality of wheels all arranged to evenly distribute the load overa maximum of Yground surface and in such manner as to impart the maximum of stability to the vehicle-under all conditions. Another object of theinventionfis to providel a multi-wheeled vehicle supporting truck in which the lwheels are arranged for interdependent and relative up and down movements to accommodate themselves to road surface irregularities while maintaining even'load distribution to lall wheels. l

Another and important object of my present invention is to provide a vehicle supporting truck of this character wherein the brake torque load is maintained in balance and the tendency of the rearmost wheels to kick up when the brakes are applied is eliminated. The construction of my improved truck is further such that, as contrasted to the troublesome kick-up encountered in most such truck assemblies of my knowledge, both the front and rear wheels as supported and connect-y ed in accordance with my invention actually have a downward movement, o rxsquatting tendency, Whenthe brakes are applied, whereby the torque load ,will be` evenly distributed to vall wheels and Wear on the tires greatly reduced.

Another andalso'important object of my present invention is to provide amulti-wheeled supporting truck wherein the. transversely spaced Wheels-of each row are staggered or offset in the longitudinal direction. The wheels are thus so positionedv that ythey will not all at once come in contactwith transverse expansion joints in the highways, but so that a part` of the Wheels will rst meet the joint before the following wheels do, so that the whole weight supported on the Wheels will not come upon the joint at the same time. This has been a troublesome factor in heavy duty highway equipment,=and it has been found that where the Wheels are all transversely aligned there is a marked tendency for the sudden loadl placedl upon the expansion joint to cause damage to the concrete adjacent thereto.

These and other more detailed and specific objects will bedisclosed in the course of the following specification, reference being had to the accompanying drawings, in which- Fig. 1 is a plan view of the rear portion of a heavy duty truck or trailer chassis showing my improved supporting truck connected thereto, and with a portion of one side of the chassis broken away-to better lillustraterthe suspension 2- and connection between the wheels at that side of the truck. j

Fig. 2 is a vertical cross section taken substantially along the line 2-2 in Fig. 1.

Fig. 3 is a side elevationof the truck as shown in Fig. land illustrating the differential action.

of the wheels.

Fig. 4 is an enlarged longitudinal sectional view taken substantially'alongthe line 4-4 in Fig. 3, and particularly illustrating the differential connections between the individual Vwheels of one of thefour pairs making lup the supporting truck.

Fig. 5 is an enlarged side elevation of the truck in Fig. l which illustrates the walking beamV action of the wheels, and with certainvparts shown in section and `with the `near wheels ofk -amodied construction of the supporting truck.

, Fig. 8 is asimilar View but illustrating a further modification. f

Fig. 9 is a side elevation partially in section,

and with certain parts omitted and illustrating still another modification of my invention.

Fig. 10"A is an enlarged detailed cross section along the line Ill-l0 in Fig, 9. l

Fig. 11 is a view similar to Fig. 9 and illustrating still anothermodiiication of the invention.

Fig. 12 is a detailed cross sectional view along the line l2-|2 in Fig. .11.

Fig. 13 is a similar view taken along the line I3-.I3y in Fig. 11.

Fig. 14 is a side elevation on a reduced scale similar to Fig. 6, but illustrating the application of my invention to a heavy lumber or timber transport truck.

Fig. 15'is an enlarged cross section along the line [5--15 in Fig. 14.

Fig. 16 is a side elevation of a dual wheel modification of my invention, the near wheel being removed and its axle shown in section.

v Figures 1-6 v In carrying out my invention as disclosed in this portion of the drawing, I provide an eightwheeled supporting truck which comprises four essentially identical dilerential wheel assemblies indicated generally at I6, l1, I8, and I9. Each of such wheel assemblies comprises a pair of wheels and two assemblies are mounted forward of the others so that the eight wheels are 3 arranged longitudinally spaced rows or gangs of four wheels each. l

This eight-wheeled truck is arranged at the rear of al vehiclepchassisbindicated.' generally at A, having side beams or Channels B and C, and for supportably connecting the truck and chassis 4 distance at which the trunnion ends 3| and 32 are spaced. The importance of this staggered arrangement will presently appea r It may fi-irth'er'l be noted` jat. this-:point that throughout all modifications of my present inven- ...tion it is understood I may employ any of the I provide forward of the rear ro-W of wheels a transversely extending tubular memberortube and forward of the front row of Wheels a simi.-A lar member or tube 2|. Y

These tubes are connected to the chassis by various wheel differential assemblies of my prior SUIS; 'Patents Nos. 2,208,599; 2,208,600; 2,209,093; 12,209,094; and 2,209,095 all issued July 23, 1940; l0.,

2,217,816 and 2,217,817 issued October 15, 1940;

"2,222,857 issued November 26, 1940; Re. 21,685

rear brackets 22 and front brackets .23.respectively, and which brackets have upright4 portions 24 riveted or otherwise secured to outer vertical surfaces of the channels B and C, and lower base or rest portions 25 similarly.securedto.the underv sides of these channels. From this L-shapedfor asV will be evident hereinafter, this construction in addition to reducing' weight contributes materially'tlateralstability andstrength of the truck as a Whole.

Each vdual and differential wheel assembly I6' through- I9 is identical with the others and for convenience sake only one'will be described in detail herein.

Thus the wheel pair I6 includes transversely other, transversely in and-'through a differentialmechanism including a `main, 'hollow housing member 33 having bearings -34 '(F'ig.- '4) to'rece'ive the trunnions. Interiorly of the housing'the ends 3| and.32 are provided with gearsf35 and 35` which-mesh with each other. The forward end of the housing member 334v is forked at^31 andv provided with Widely spaced and v'widespread bearings 38 and 39 which ar'epivotally'mounted upon the tubular cross member 20 at opposite sides of the bracket bearings 28 l(FigL l), and the entire differential assembly isthusl arranged for swinging movements with' respect to the-vehicle ,A

in an upright longitudinal'plane.

The gears and 36 act to' differentially connect the wheels l 6e and IBb in suchvmanner that,

as4 either-moves upwardly, by -swingingmove- 5 ments of its associated cranked axle,- the other will move'downwardly a corresponding' distance. The wheels thus accommodate themselves to inequalities in the road surface over which'fthey travel and maintain equal-1 load distribution.' at all times.

It may here beV noted 'thatthis type of differential mechanism, with'the `wheel axles pivoted on parallel axes, spaced in a fore and aft plane, and with the axles trailing rearwardly from their pivots, is disclosed in my U. S. Patent No. 2,217,817 issued October 15, 1940. In that patent, however, the crank axles were of uneven length to compensate for thevspaced pivots and to bring the axes of rotation of the respective wheels into alignment. In the present case the axles 29 and 30 are of equal length and the wheels IBa and I0b are accordingly staggered or positioned one forward of the other by a distance equal v to the and 2,227,762 of January 7, 1941; 2,232,275 issued February 18, 1941; 2,232,972 issued February 25, 1941,' 2,244,853 issued June 10, 1941; and 2,254,451 and 2,254,452 issued September 2, 1941 wherever thesev are suitable and applicable.

"The differential movementsy of Atheawheels d'6@ and A|159 may-be limitedto a predeterminedrange by ifillingin appropriate teeth of the vgears 35 andv As startedv above-'thefour whe'el assemblies lt. I1; I8.v and 9 are identical 'in construction'. k'Thus the 'other rear wheel assembly l'lfincludes difer entially connected wheels '|18'. and 'lbsupporting and i connected I to aL diierential mechanism includingI a housing- -M'pivoted by bearings 42.' at

its forward .endiupon' the opposite end'of tubular4 member 20. 'SThe-wheel-assemblyf'l 8, immediately forward of' assemblyE l0 previously described in detail, includes di'erenti'ally operatingwheels e-TED- supporting' "'a' 'i differential f mechanism l housing 43 journaled by widespread bearings-M at its'- forward end upon the" forward'itub'ular member 2|. The remaining forward wheel assembly I9 vcomprisesdifferentially operating w-heels Il ila-l 9-b and ahousing-l pivoted v lziybearings- A6- at theoppOsite endl ofthe tubular member` 2|. =The lvarious'wheel1assembliesl thus arrangedare heldin placev against laterali displacement by the bracket bearings y28 and by plug nuts 'dl'closing the 4ends of the' tubular cross meinbers 20'and 2|.

It will be noted, that'by'vvirtue- 'of the previously referredto offsetting ofthe pivots-for the-various cranked axles, i n a fore and-aft plane, thatin each front and-rear row of wheels two-wheels will' be positioned slightlyforward of'theremaining two. Thus `the wheels will meetexpansion joints on the highway Tat differenttimes, and distribute the load more evenly at each side of such jointsall to the `end that the previous tendency to damage the roadbed by this type of heavy duty equipment is alleviated. It will furthervbe-observed that all of the differential mechanisms are duplicates and are interchangeable butthatas here shown in Fig. 1, they are reversed-'or iio'pped over in such manner vthat.' the'outer Wheels of each wheel pair are forward of v,therespecti-Ve inner wheels of the-sinnek pairs.

Referring particularly `to Fig. 5 it WiIlbE'Seen that an equalizing and spring suspension cone nection is made between thefront and rear pairs of wheels here indicated atr ||5-|8.v kThe same connection is made at the 4opposite 'side between wheel pairs I1 and J9. For' this purpose I provide a cantilever leaf spring llaattached atits center to a bracket 49 having a r sleeve bearing v50 at its-upper `end journaled upon the rear tubular member 20 in the space provided between the rear bracket bearings 28l (Fig. 2). Bolts 5|lr and a lower clamp plate 52 Isecure 'the spring 48 tothe bracketasSclearly'indicated, and said bracketfds, of course, formsxin effect a supporting connection between the springend-the vehicle. Thespring 118` .extends in. aigenerally longitudinal direction and may oscillateabout the axis of member 2U in upright planes at its ends. The rear end of ,the spring extends beneaththe rear differential mechanism housing 33 and is pivotally connected thereto by shackle links 53 connected by a pin 54 to the spring and by a pin 55 to an eye 5B formed at the rear of the housing. The forward end of the spring extends beneath the rear end ofthe differential housing 43 of the forward wheelpair I8 and is pivotally connected thereto by shackle links'51 attached bypin 58 to the spring and by a pin 59 to an eye 6U Aat the rear of said'housing. The spring 48 itself is vof 'a -he'avy duty type but may embody a helper spring 6| loosely connected by shackle loops` 62 ina conventional manner, if desired or required.

At the rear of each differential housing 33, 4I, 43 and 45 an eye or apertured lug 63 is provided and from each there runs a cable 64 upward overv a pulley 55 on the adjacent side of the chains A and then forward to an operating device (not shown) by which said cables may be pulled upwardly Aand forwardly when desired.

In Fig. 6 I show the truck thus constructed a arranged at the rear of a fuel transport truck D which is attached by the usual fifth wheel mechanism E to a tractor F of usual form.

In operation, not only will the individual wheels of the various wheel pairs have a compensating, diierential up and'down motion as they accommodate themselves to transverse irregularities in the road surface over which they travel, but the front and rear aligned wheel pairs or assemblies will also have an. equalizing action for longitudinal road surface irregularities, due to the walking beam or equalizing vaction of the springs 48 connecting front and rear aligned wheel pairs. In other Words, a downward movement, of say the front wheels lof Fig. 5, will cause a downward swinging movement of the forward end of the spring 48 about its pivot upon the rear tubular member 20 and a, corresponding upwardv movement of the rear end of the spring which will be translated to an equalizing upward movement of the rear wheels I6. VSuch equalizing action is, of course, in addition to the spring suspension of the wheelsafforded by the springs 48-6l for absorbing road shocks.

It may here be noted that the springs l48 need not necessarily, as here shown, be pivoted or'fulcrumed to the vehicle coaxially with the rear differential housings 33--4 l ,or upon the rear tubular cross members 20, to operate as described above. For example, the spring carrier brackets 49 might be pivoted by separate pins (not shown as this variation is obvious) to the rear brackets 22 or even to separate supports fastened to the vehicle, and the springs will then still oscillate to serve their walking beam and equalizing purposes. I do not, therefore, limit myself tothe coaxial pivot arrangement as herein shown throughout the drawing. v

Attention is called at this point to the importance of the distance between the front and rear tubular members 20 and 2 I, with reference t0 the lengths of the differential housings 33 etc., andof the springs 48. To best advantage the proportional relation of these dimensions is so chosen that, as seen in Fig. 5, the forward shackle links 51 incline upwardly and forwardly in what-may be termed the normal positions of the parts, or while the vehicle is operating over comparatively level surfaces. Such position of the links 51 is important in that it provides a maximum of flexibility and smoothness in the up and down movement of the forwardy wheels. For example, should the front wheels I8 (Fig. 5) dropinto a hole in the road surface, the downwardmovement of the rear end of the housing 43 would further angle the links 51 forwardly until a condition might come to pass in which the points 2 I, 59 and 58 would reach an alignment or straight line. As the front wheels I8 then crawled up out of such hole the toggle relation of the links 51y and housing 43 would fold upwardly at point 59 with greatest ease andwith-a minimum of spring reaction to overcome. On the other hand, and as will be clearly apparent, if the proportions were such that the links 51 normally inclined upwardly and rearwardly, or even straight upwardly, a locking effect might be produced under the conditions set forth such as to offer considerable resistance to the operation. l Y.

By pulling uponL the forward cables B4 vit is possible, as seen in Fig. 6, to raise the front Wheels out of engagement with the road surface while leaving the-rear wheels as sole supports at the rear end of the vehicle. The reverse is,of course, possible andthe rear wheels might4 be raised instead. The utility of this feature oflmy invention lies inthe vfact that it enables a truck or transport running empty to operate onfewer wheels to save tires, or in case lof damage to either front or rear tires, allows the truck to proceed without damage-to nearest point lfor repair.

Itv is also possible by adjusting the cables 64 to notvonlyselect the working level of the wheels or mean operating angles of the various differential mechanisms, but by selective adjustment of the cables at each side,to adjust the cant or..

transverse level of the vehicle. In fact, and by for instance pulling on the cables on the inward side of the vehicle as itv travel-s a curve, while paying out the` -cables on the other side, or even holding them against paying out, it is possible to bank the vehicle 0r so tilt it inwardly as to largely counteract the normal outward rolling tendency and permit of higher speed operation.

vIt will be noted that not only are the wheels all evenly spaced across the width of the vehicle but that the widest possible bearing is secured upon the relatively wide or long tubular cross members 20 vand 2| with widespread bearings between the various differential assemblies and these tubes. All of these factors Vcontribute greatly 'to lateralV stability. l Further advantage is vsecured by the low level location of the heavy parts of the truck, such as the springs 48 and differentials, which weight distribution lowers the center of gravity to further increase stability and make high speed operation possible. It is for this reason that I illustrate this modification of my invention in Fig. 6 as applied to a l-ow slung fuel transport, which "equipment operates at high speed on the highways and which heretofore has given much trouble ydue to high center of gravity and lateral inst-ability.

Although not jhere shown in detail, since they may be wholly conventional, the various wheels of my truck are all equipped with brakes. When these brakes" are applied an advantageous action takes place Vwhich overcomes faults in many previous tandem wheel truck-s. Without some means to counteract it, there is a well known and marked tendency of a tandem wheel group to kick up at the rear as the brakes Iare applied, due to a tendency of the entire assembly to rotate about the braked wheels. As a result, the greatest load is thrown on the forward wheels which then assume nearly if.. not all .of the brak:- ing action as the Vrearwheels kick. up and lose contact with the road surface. The tremendous load and strain on the front tires may well be imagined.A f Y Consider now` the action as the front and rear wheels of Fig. are braked. Since the front wheels |8 have, of course aftendency to continue rotation there is setup a force acting about the centers of these wheels as indi-cated bythe arrow 66. This force is v'obviously downward iflthe truck is traveling to the right as viewed in the drawing. There is 'thus -a tendency of `the-front wheel assembly to squat kor settle downward and this 'force is transmitted directly to the spring 48 and through that tothe pivot for the rear `differential housing 33,- causing a downward pull thereon'as indicated by 'arrow 61. Thisdown movement is carried back through housing 33 and through springl 41 and it results in a downward force? upon :the rear wheels i6, as indicated by f pinned at 86 to the spring'fandat 8'l .to said housarrow 68, which counteracts Aand overcomes the tendency of the rear wheelsto kick up. There results in sum,then, a marked-tendency for the entire truckv to settle as thebrakes are applied; holding allof the wheels in road' engagement, and greatly increasing braking effectwhilevreducing tire wear.

Throughoutthe modifications of my invention now to be described only the wheel pairs lor dual wheel assemblies on the near side of the vehicle areshown and described but it will be understood that the same assemblies are provided on the opposite sides of` the vehicle. Corresponding frame parts of the vehicle are indicated throughout by-the same reference characters heretofore applied.

n Figure f7 In thisy modification I illustrate front and rear tubular. cross members 69 and '|0 as supported from the Aframeside B by brackets '||l and 12 similar to those previously described. Arranged to the rear of Ithe forward cross member 69 isa pair of wheels, indicated generally at -'|3, and similarly arranged behind the rear cross memberf 10 is another pair of wheels '|4. These wheels 13 and '|4 are journaled at the rearendsoi lcranked axles, indicated throughout .at 15,and the axles supportedby theforward wheelzpair 'I3 are .piv-

oted at forward ends in a diierential mechanism housing -16 which is -pivotally mounted at its forward end Tl upon the forward cross lmember 69 for. up and down swinging movements ina longitudinal plane-with respect to the vehicle. In similar fashion the axles A|5 supporting the rear wheel pair 'I4 are pivoted in a differential mechanism housing -'|8 pivotally connected at its forward'end to the'rear crossmember l0 for corresponding swinging movements.

'Ihe forward trunnion or pivot ends of the .cranked axles 15 are pivotedin the respective housings 'I6 land '|8 in vertically-spaced orsuperimposed relation and interiorly of the housings the` axles are connected 'by meshing gears 80 ,so that-the axleswill have .diii'erential up 4and down movements at opposite sides of the` building. ThusA as either axle of the wheel pairs '|3 or 14 moves upwardly the other axle of the same pair will have lacorresponding downward movement. This type of differential mechanismis essentially the sarneas that dis-closed -in -moredetail in my prior Patents, 2,217,816 and 2,244,853 previously identified.

, I. also provide in thismodincation'of" my; in-

ingl VThe rear 'end of Yspring textends over the rearwardly trailing" end of the 'rear housing "18. and Yis similarly vconnected thereto by shackle links 88 pinned at 89 to the spring andv at190 to the rear end of said housing. lItwill be. noted that the'spring 8| is supported above the differentialy housing With the shackle links and 88 in depending positions,l and that ythus' there'is greater` clearance providedrbelow the housings than'i's present inthe construction of Figures 1 through 6. This may bev of advantage'in such type of equipment as lumbering trucks 'or military vehicles or in any vequipment operating over ground having stumps or similar obstructions.

It will be course be obvious that, the operation of this modification .in-Figure 'Ibis essentially identicalwith that previously described and rit is thought that no detailed descriptionshouldI be required. l Figure 8 Inthe modication of my invention hereillus'- trated I showfront and rear tubular cross members 9| and 92 supported lby brackets '93 and 94 from the frame side B andvwith front and rear. wheelpairs and 98 arranged respectively to' the rear of said cross members. The individual Wheels of these wheel pairs 95 and 90, are jour: naled in the rear ends of cranked axles 9`| and the forward parts` of these axles are-provided with pivot or trunnion ends 98 journaled transversely and in parallel, superimposed positions through front and rear differential housings99 and.|00. Interiorly of said housings 99 and |.00 the trunnion ends ,98 Aof the axles areconnected by gears I0| to impart; a differential action. to the axles in exactly the same manner as previously described With reference to Fig. 7.

In this case,.however, the differential housings 99 and |00 are positioned below the cross members 9| and 92 and are provided with upwardly extending bearing portions 02 which are pivotally mounted upon saidcross members. The housings 99 and |90 are then provided with rigid rearward extensions or armsy |03 and. |04 respectively postioned between the front and rear pairs of transversely spaced axles `91. and extending approximately back to the centers or axes of the wheels 95 and 93. The pivotal suspension of the housings 99 and |00 is obviously such that they may oscillate in an upright longitudinal plane with respect to the lvehicle and in sodoing the rear ends of the'arms |03 and |04 will move Aupwardly and downwardly. A cantilever leaf spring |05 is secured at its center by staple bolts |06 to a spring bracket |01 which is journaled at |08 upon the rear cross member 92in a manner similar to that shown in the previous modification. The spring |05 extends in a lengthwise direction above the differential housing for opposite up and down movements at its respective front and rear ends and the 'spring is connected by shackle links |09 at its forward. end to the rear extremity of the forward arm |03..

Said shackle links are pinned at I I to the spring .and at II I to said arm |03. The rear end of the spring is similarly connected by shackle links II2 to the rear extremity of the arm |04.over which the rear portion of the spring extends. These shackle links II2 are of coursepinned at |I3 to the -spring and at |I4.to the arm |04.v

Here again it is believed that the operation of this modification, being identical in.v all essential respects to that of previous modifications, it will be readily understandable without detailed description.

Figures 9 and 10 In this 'portion of the drawing I illustrate a further modification of my invention which differs from those previously described most particularly in the form of springsuspension and equalizing action which is employed. The same type of front and rear tubularcross members I I5 and I I6 are supported from the frame side B by brackets I Il and II vand front kand rear wheel pairs ||9 and |20 arev arranged tothe rear of these front and rear cross members, respectively. The individual wheels of each wheel pair I9 and |20 are journaled atthe rear of cranked axles, indicated throughout at |2|, and the forward trunnion endsv |22. of these axles are journaled in parallel superimposed relation in front and rear differential housings |23 andl |24, essentially identical to those indicated at 99 and .|00 in Fig. 8. These housings |23 and' I 24 have @bearing portions |25 at upper ends by means ofr which .they are pivotally suspended upon the respective front and rear cross members |I5 andI I6 so that the housings may oscillater in upright vlongitudinal planes-with respect to the vehicle. Interiorly of the housings |23 and |24 the trunnion ends of the axles IZI are differentially connected by gears (not here shown) but in exactly the same manner as illustrated in Figure 8,- and so that upward movements of either wheel .pair I I9 or |20 will be translated into an equal downward movement of the other wheel of the same pair.

In lieu of the cantilever leaf spring acting as a. walking or equalizing beam, as previously described, I employ in this modification of my invention a connecting linkage arranged directly between the front and rear housings |23 and |24. For this purpose the front housing |23 is provided with an upwardly and slightly rearwardly extending arm |26, while an apertured lug |21 is provided on the forward side of the'rearhousing |24. It will at once be obvious that if a rigid link were extended between the upper end of the arm |26 and the lug |21, the swinging movements of the forward housing |23 accompanying up and down movements o-f the front wheels IIB, would be translated to opposite movements of the rear housing |24 to oppositely adjust the rear wheel pair |20. Thus an equalizing action would be 'obtained between the frontv and rear wheel pairs.

In` accordance with my invention/I provide Ya link mechanism for this purpose but one employing not only spring means for absorbing road shocks but length adjustment for raising and lowering the wheels, as will now be described. Pivotally connected by a pin |28 to the lug |21 on the rear housing |24 is a pair of spaced bars IZB-|30 which at their forward ends are rigidly secured at I3| to an end plate |32. Assembled in interlockingA relation to the bars |29---I30 is an-r plate |36.,y Theend plate |32.is notched at |37 at points .spaced at to the bars I29-I30 for the slidable reception of the bars |33-I34;l while in similar fashion the plate |36 is notched at |38 at 90 with respect to the bars |33-I34 to slidably pass the bars I29-I 30. The arrangement is thus such that the two end sections of the link comprising the bars |20-'I30 and |33-I34 may have relative endwise movement while being maintained in lengthwise alignment. l

lThe forwardy ends of the .bars |33-I34 are rigidlysecured by welding or` other suitable means along diametrically opposite lines to alhydraulic cylinderI'39, and to the end of this cylinder there is affixed a clevis |40 which ispivotally attached bya pin |4| to the upper end of the arm |26 extending from the forward differential housing |23. `A heavyexpansion coil spring |42 is arranged between .the e'nd plates v|32 and |36 and is retained in place by the cage-like structure made up bythe bars 'I29-I30 and ISB-|34.

' In operation, itwill be apparent that an equalizing action will nowvbe obtained such that, as either thefront orrear wheel pairs move upwardly in response to irregularities in the road surface, the other wheel pair will be moved downward by the I link connection between the respective differential housings |23 and |24. In

addition, the spring |42 is so arranged-as to per? mit limited and yieldableV expansionl and contraction of the linkage connecting4 the front and rear pairs' in such manner as to cushion the wheels against road shocks.

Thehydraulic cylinder |30 includes a piston |43 from whichthere extends rearwardly a pistonrod |44 projecting at its rear Vend through a packing gland |45 into proximity to the front end plate' |32. Normally, the piston ,|43 will stand ata forward positionl within the.` cylinder |49, vas here shown; and the rear end of the piston rod. |44 will clear said end plate/|32 to` permit free movement of thefspring |42 during its shock absorbing action. However, fluid or air under pressure maybe admitted to the cylinder head of the piston |43, as through aflexible line |46, kand when this is done the lpiston will be moved rearward until .the rear extremity ofthe piston rod |44 engages rthe end plate |32. This action may be continued to such point thatthe spring |42 willthen be `compressed and the affective length of the link between front and rear differential housings will-be increased to any selected amount Within the range provided by the piston movement. AIt will. be obvious that such extension of the linkage will result in raising the wheels |9| 20 with respectto the vehicle to adjust the'l mean working. angles of the parts wherever this may be required. Not only may the working level of the vehicle thus be selected, within limits, but by selectively operating the cylinders |39 at opposite sides of the vehicle or at `one side only, the transverse level or cant may be adjusted. It is of course possible that under automatic lcontrol the .transverse level of the vehicle may be adjusted whenl traveling a curve to counteract the rolling over 'tendency to a large extent and so permit higherspeed operation under these conditions. i

In this modification of my invention vI also illustrate vacuum brake operating mechanisms for the respective wheels. Each said mech-v anism comprising the conventional operating unite-|41, the. plunger rod |48- and lever |49, is arranged upon the axley |2| 'of the associated wheel and the brake actuating -shafty forl that ll wheel |50 is journaled in the corresponding axle |2|. Thus the entire brake mechanism for :each wheel swings as a body with the Wheel maintaining .proper relationzwith the brake mechanisrn thereof Without employingt any compensatingllinkage I Figures 11, 1.2 'and 13 lIn this modification ofxmy invention I again employ front and rear tubular cross .members and |52 supported from the frame side B by brackets |53. and |5.4,.and;;to the rearxofthese cross.- members .Iarrange `.front and rear wheel pairs y|55 and |56, respectively. The individual wheelsof .thezwheel pairs. |55, |56l are journaled attherrear ends .of Acranked axles,. indicated throughout: .atx l1.51., but dilering from previous `modifications,.. the forwardeends of these .axles are .jcurnaledby .bearings 58 :directly upon the respective cross-:members |5| and |52.

I then employ differential connecting .mechanism for the.. axles..|51, identical Iin allessential 4respects tozthat.'showncin'detail inmy patent No. 2,236,734,1.previously :referred to.. As .here shown, such n differential mechanism i includes housings .|59 land 3|'60 having depending bearings |61.- by which they .are pivotally supported upon the respectivefrlont andzrearfcross membersV and |52 forY oscillating movements. in upright longitudinal planes,.independent of the .cranked axles. Journaled near-.the upper endsof :the-housings v|591and .|60 at ,opposite sides thereof are coaxial shafts |62 eachiof'which,':interiorly of the housing, `isiprovided. with..a gear sector |63.

`These. gear sectors mesh .with apinion |64 .so that rotation of .eithenshaft |162 ywill be. translated vto an equal or oppositeurotation of the otherv Rig- `idly :secured .to the shafts |62, outside -of .the housingsyare springbracketsv |65 to whichthe forward ends of1semicantilever1leaf springs .I6-l are rigidly secured by staple bolts |61.V There is The arrangementaisfthus obviously such 'that the upward movement of-.eitheixaxle 51. of either pair will .so oscillate the. associated .spring-.|66 las to 4operate the-sector fgears :163' and pinion :|64 to differentiallyitranslate #such .movement to the opposed-sprifng"|166` and-.cranked axle of theo-ppcsite whe-el of; the same pair. Thus the individual wheels havefa :differentialaction 'through the. springs '|66- .and inz'additionfthose springs act Lto cushion; the awheelsrgiindivdually against. .road shocks.v l

In lav fashion similar 2te.. thatsdisclosed in' Figure 9, I here @connect thefront :and rear ydifferential housings |59 and1f|60 .by :an equalizing linkage, but which in this-;:case,1emb.odies. no spring since the cushioning :and I :shock Aalosorpt'ioni `.effect is obtainedy in. the differential. mechanisms .themselves. As here shown, the rear differential housing |60 is provided withfa depending arm |1| to cof which is `pivotally attachedsby a..pinf|12fa yoke l |13 which .is interlockingly engaged *with 2a rectangular yoke :|145 The fbight or crossportion of the yoke |13 is rigidly `secured by'vveldingor other suitable ,means tto the. forward .endgof fa hydraulic cylinder .|16 which .iis retainedwithin the .cagelkw-construction; allorded byythel interlocked my'invention as contrasted to the tandem wheell 12 yokes.. A link rod |11-.is rigidly. .secured at |18 tothe forward end of the yoke |14 and at its for:- Ward end is providedwith aclevis |19 which is pivotally attached by a pin to an upper rear corner of the forward differential housing |59.'

y .Apiston A| 8 is provided within the cylinder. |16 and has a .piston rod |82 extending out-rearwardly through a packingI vgland |83- into contact with the rear bight of cross .member |14. Provision is made by a flexible line |85 for admitting uid under pressure to the cylinder |16 forwardly of the piston I8 i Normally the linkage 4thus described will so connect the differential housings |59 and |60 as to provide an equalizing action between the front and rear wheel pairs |55 and-|56, exactly as has been previously described. In other words, upward movement of vthe forward wheel pair,y for example, asv it encounters arise in the road surface over Vwhich it travels will'be translatedto an equaliz'ing downward movement of the rear wheel pair and vice versa. By admitting fluid or air under pressure to the cylinder |16 to project the piston 18|' and pistonrod |82 in a rearward direction, the effective length of the linkage connecting the differential housing may-be decreased at will to so vertically adjust the positions of the wheels |55 and |56. -with'respect to the vehicle. Here again selective adjustment of the linkage 'on the opposite side vof the vehicle may be employed for -canting the vehicle as it travelsl around curves or for otherwise adjusting the transverse level as will be required.

Figures1`4 and 15 I here-illustrate the principles of my invention as previously described applied to a heavy duty timber orlumber truck comprising the usual tractorl G'to rwhichl aneight-wheeled truck, in-v dicated generally at H, made up in accordance with any modification of my invention is applied as --a rear support. Of specialV importance here is the ease in whichthe tubular cross members, indicated at |86 Aandltl, adapt 'themselves to connection to *a longitudinally extending tubular reach member v|08 for 'forming'the main `backbone of the truck. The reach tube |88 may be rigidly secured by sleeved castings l 89 to the cross tubes-'|86-181 very conveniently, and such cast# ings |89 may, Aas seen in Fig. l5, have tubular tubular portions |90 extending the full width of the cross tubes between'the bearings |9| of the differential mechanism, Iindicated generally at |92. At the forward end of the vreach tube A|88 will, of course, be attached by a wheel mechanism |93 'of any yconvenient form Vto lthe rear end of the tractor G. 4

VSuitable bolster castings |94 `provided with end stakes '|95 may -be secured in spaced relation along 'the length of the reach tube |88 to providecradles Vfor the `reception of the timbers, .indicated at I, held in place by chains J. Obviously the .foregoing construction is such that only a skeletonized frame work is required for fa .truck or transport of this character, but at the same time the maximum of lateral stability issecured consonant with the heavy loads .ordinarily car.'- riefdlby this type of equipment..

l Rigi/me 1.6 Ighere illustrate a dual wheel modiiicationof arrangements previously described, and with nd-ividual spring housing.

suspension for the differential "A tubular cross member |96 is supported from the frameside B bya bracket 91 and forexam- .ple I have shown a differential housing-|98 of exactly the same type'as that illustrated at 33 in Figure as connected to this cross member. `Dual transversely spaced wheels |95)v are journaled at the rear ends `'of the cranked axles 200 which are differentially connected inside the housing |98 to provide opposite' compensating -up and down movements for the wheels.

In lieu of the various equalizing mechanisms previously described, the wheels I 99 are cushioned against road shocks by an expansion coil'spring 20| braced at its lower end against a spring seat 202 pivoted at 203 to a rear portionofthe housing |884 The upper end of the spring 20! is similarly braced against alcap 'member 204 pivoted at 205 to a bracket 200 secured to the frame-side Bf 'Thespring seat 202 and cap 204 are held in alignment by telescopingtubularlmemb'ers 201 in a= well known manner, Obviously this constructionis such that the-wheels |99 in addition to their differential compensating movements may move upwardly and downwardly as a body while yieldably cushioned against road shocks by the spring 20|. l

It will be noted th'ata dual wheel assembly of exactly the same characteristics' may'also be --provided in the structures for example'of Figures 7 and 8, by merely eliminating the forward wheel'. assemblies and substituting semicantilever springs for the remaining wheels 'while securing said springs at forward ends v'tothe vehicle. f Y

The cable arrangements for raising and lowering the wheels as illustrated in Figures 1-6 may of course be carried through to other embodiments of the invention, although they are' not here shown for convenience. -f

It is understood that suitable modiiications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my `'invention, what I claim to be new and desire to protect by Letters Patent is: y' 'l 1. In a tandem wheel supporting vtruck for a vehicle frame, a pair of transversely extending parallel tubular cross members secured tothe frame, a separate row of transversely spaced ground wheel pairs positioned rearwardly of each l cross member, means diiferentially connecting the wheels of each pair, and means supportably connected to the wheel pairs and swingable on the cross members for transmitting load forces to the wheels while permitting limited up and down movements thereof with respect to the vehicle.

2. A vehicle supporting truck, comp-rising in combination, a pair of differential wheel connecting mechanisms arranged one rbehind the other and each swingably connected to the vehicle for swinging movements in upright planes with respect thereto, separate wheelpairs supported by each of said mechanisms and the wheels of each pair being connected for movements in opposite up and down directions by said differential mechanisms, a longitudinally rigid connection betweensaid mechanisms movable endwise by movements of said mechanisms and so'connected thereto as to translate up move-v ments of one to down movements of the other, and said differential mechanisms including spring means pivoted on an axis coaxial` with the axis about which `the rear mechanism swings 14 and yieldably urging--therespectve wheels downwardly and operative to absorb road shocks;

3. In a vehicle supporting truck, the combination'comprising a pair'of members arranged in tandem relationship and each pivotally connected at its forward end to the vehicle for up and down swinging movements at itsy rear end, a pair of ground wheels arranged adjacent each said memberwith the wheels of each. pair positioned at opposite sides ofthe associated member, crankedaxles supported -by the wheels and extending forwardlyv therefrom Aalongside vthe members and pivoted at forward ends to said members, differential mechanisms connecting the respective axles. for translating yupward movements of either to downward movements of the other, and means extending between the front `and reanwheel assemblies for .translating up `and down movements ofthe front or rear wheel pairs to opposite movements ofthe other.

4..'In a vehicle truck assembly, the combinationcomprising members each pivoted at one end to the vehicle and `extending rearwardly from their pivoted .ends in tandem relation, ya pair of cranked axles pivoted at forward ends to each of thesaid members and extending rearwardly therealongside, ground wheels `iournaled on and supporting the rear ends of the axles, means supported by said members and connecting the axles for diiTerential-up and down movements, and means connecting the said kmembers for urging either downward as the othermoves upwardly. i Y

5 In a vehicle truck assembly, the combination comprising members each pivoted at one end to the vehicle and. extending rearwardly fromtheir pivoted vends in r`tandem relation, a pair of cranked axles pivoted at forwardends to each of the said members .and extending'rearwardly therealongside, ground ywheels journaled on andfsupporting the rear ends ofthe axles, means supported by said members and connecting the axles for differential up and down movements, and means connecting the said members for urging either downward as the'other moves upwardly, the said axles vbeing of equal length but being pivoted to the said members in spaced positions forwardly and rearwardly with respect to eath other to offsetcertain of thewheelsforward of the others. A

6. In a vehicle suspension assembly, a pair of memberseach pivotally connected at its forward end to the vehicle for up and down movements at its rear end, cranked axles extending rearwardly alongside each member` and pivotally connected at their forward ends to the said members, differential mechanisms connecting the said axles, wheels Asupporting the rear ends ofthe axles, and means yieldably resisting upward movementsv of the said members. Y

7. In a vehicle supporting truck for a vehiclehaving transversely spaced longitudinally .extendingframe side members, at least onemember pivotally supported at its forward end `to' at forward endsv to said pivoted members, differential mechanisms supported by and movable' with sald lpivoted members and connecting thel axles to translate up movement of either wheel amasar of the wheel pairs Vto vdown movements' of fthe resisting'upwardmovements of the wheels;

8. `In a 'rehicle' supporting 'truck'oi .the character described,v front and rear. bracket members .oni the vehicle, f tandem V'arranged dinerenr tial. housing members pivotally attached tothe l bracketmembers and depending therefrom `and havingL "rearwardlyextending upwardly and i downwardly swingabl'earms, a ground wheel .po-

sitionedat eachside =of each arm, crank axles supported bythe: grou-nd wheels and extending forwardly `therefromv and '.pivotally` connected l tozrthe :respective members.l differentially operating-means 4on .the :members connecting the forwardends ofthe cranks,;and spring-.means connected between- :the vehicle. and the rear ends ofzthe: arms for yieldably resistingI upwardmovements ofi thelarms.'`

, nisms vcarried by the membersxand connecting they crankaxles, a leaf .springIconnected-at its ends.. tcithe said members rearwardly of their respective pivots, and said' spring vbeing pivotally connected intermediate its-endst'o the frame on a common center withthe pivoted end of' the rearmost supporting member. y

; A vehicle supporting. truck Aof the character: described, comprising` a v'pair of 'differentialwheel' connecting mechanisms arranged in tandem': relation; andi each. swingably `connected at itsffoma-rdf end toA the-vehicle'for up and down swinging. movements at' its rear end, separate Wheelpa'irs supporting `the rear ends of said mechanisms and connected thereby `for interdependentup and down differentialf movements,

` other wheel of the pair; and. means for yieldably anfarm. :extending downwardly `from-the rear diierential 'mechanismand anotherk arm extendingupwardly from'the front mechanism, and a connection member extending between thearms toztranslate up: movement of either-wheel pair to downzmovementsof` the other.

l'l'yAvvehicle supporting truckv of'rtheL character described, comprising a -pair of d-ierential wheel: connecting mechanisms arranged in tandem. relation andeach swingabl'y connected' atits forward'l end to thevehicle-for'up and down swinging-V movements at its rear end,Y separate wheel'- pairs supporting the rearendsA of said mechanisms and connected thereby for interde-1 pendent up and `down^differential movements, arms'xextendingfrom the differential mechanisms, a member connecting saidY arms and mov'- able endwise byY upandl down movements'ofeitlier wheel pair to oppositely move the other' `wheel pair, and' means separate from sai-d connecting member.l lfor ylel'dably" -resifstingupward movementsrof? thewheels. Y

. 12. In a1 vehicle,- apair ofl wheel" assemblies eachI including two differentially;` connected" wheels and va- .c liiiferentiall housing, means in the. housings for di-ierentially"connecting.the Wheels, the forward'l 'ends ofthe differential housings beingy Divoted', to. the'. vehicle. ona .transverse axis, and springmeans actingbtweenthe hous-A ings. and upwardly .spaced points. on the. vehicle,- forv yieldabl'y, resisting .upward swinging. move-- ments .ofA the, housingssaboutv saidfpivots. v

andeach comprising apair ofv differentially operating wheels and a housing extending forwardly from between the wheels,v means insaid housings differentially connecting `vthe wheels, a tubular member secured transversely to the ve'- hicle and the forward ends of the housings being pivoted about said tubular member whereby it `acts as a light and rigid backbone connection-and vsupport for the wheel assemblies, and means connected lbetween `the vehicle and the vhousings at points to the rear ofthe Vsaid differential connecting means therein'for lyieldably resisting upward movements of the wheels.

14.-'In vehicle supporting mechanismof the character described, the combination comprising tandem arranged front and rear Wheels at eachl side' of the vehicle, vertically swinging means connecting thefwheels to the vehicle, an element-connecting said means at each side for translating vupward movements of the front wheelsto. down movement of the rear wheels, and said connecting element at one side at least/of thevehicle being adjustable in length'in such manner as to selectively raise or lower both the front land. rear wheels and thereby control the transverse level of the vehicle.

15.` In-vehicle supporting mechanismof :the character described, the combination comprising tandem-arranged front-and rear wheels at each side ofthe vehicle, vertically swinging-means connecting the wheels to the vehicle, anelement connectinggsaid'meansat each side vfor translatingupward .movements of the `front wheels `to down movement of the rear wheels, said connecting element atV one side yat leastl `of the vehiclebeing. adj ustablezin length in- Vsuch vmanner as ltoselectively -raise or lower-'both the .front and rear wheels'andthereby control the transverse level of the -vehicle, and remotely controllable power actuated means Vforso adjusting the lconnecting elemenn- Y 16.- In a yvelncle-truckassemblmthe combination comprising members each V'pivoted at lone end to thei vehicle :and #extending rearwardly a Ifromtheir ypivotfed ends: in tandem relation,`Y a

pair of cranked axfles'pivoted at forward `ends to eachl of thesaid members and extending rear- Wardly,therealongsideg-ground wheels journaled ong-and supporting. the rear vends of.' the' axles, means supported by said members and connectingtheaxlesffor differential up and :cl-own movementspfand the said faxles: being operativelyy Jarranged1 to ieffsetcertain of.l the 'wheels' forward of.theotlzrers` l?. lIn a vehicle; truck: assembly; theI combina--` tion comprising Amembers @each pivoted at one end .to the'vehicle-and`v extending rearwardly.- from their pivoted ends, a pair of cranked axles pivotedat.- forward ends toeach of thev said members.=and extending rearwardly therealongside, ground wheels `iournaled-onand supporte' the;` vehicle, a diirerential housing member'` piv-r` otally: attachedfto thev bracket member. and de'- pendirrgtherefrom and havin'ga rearwardly er#l tending :upwardly land :downwardly sir/ingable!l arm, 'a giod wheel positioned'a't each' side of each arm, crank axles supported .by the ground wheels and extending forwardly therefrom and pivotally connected to the housing member, differentially operating means in the housing member connecting the forward ends of the cranks, and spring means connected between the vehicle Iand the rear end of the arm for yieldably resisting upward movements of the arm.

19. In 4a vehicle supporting truck of the character described, front and rear bracket members mounted on the vehicle, tandem arranged differential housing members pivotally attached to the bracket members and having rearwardly extending upwardly and downwardly swingable arms, a ground wheel positioned at each side of each arm, crank axles supported by the ground vwheels and extending forwardly therefrom and `pivotally -connected to the respective housing members, ldifferentially operating means in the' housing members connecting the forward ends of the cranks, `and spring means connected between the vehicle and the rear ends of the arms for yieldably resisting upward movements of the arms.

20. vIn a vehicle supporting truck of the character described, front and rear bracket members mounted on the vehicle, tandem arranged differential housing members pivotally attached to the bracket members and having rearwar-dly extending upwardly and downwardly swingable arms, a ground wheel positioned at each side of each arm, crank axles supported by the ground wheels and extending forwardly therefrom and pivotally connected to the respective housing members, differentially operating means in the housing members connecting the forward ends of the cranks, and a leaf spring connected at its center to the vehicle and at its respective ends to the rear endsof the arms for yieldably resist-ing upward movements of the arms.

2l. A vehicle supporting truck of the character described, comprising a pair lof differential wheel connecting mechanisms arranged in tandem relation and each pivotally connected at its forward end to the vehicle for up and down swinging movements at its `rear end, separate wheel pairs supporting the rear ends of sai-d mechanisms and connected thereby for interdependent up and down differential movements, an arm extending upwardly from Athe front mechanism, and a connection member extending between the arm and a point on the rear ydifferential mechanism below its pivot to translate up movement of either wheel pair to down movements of the other.

22. A vehicle supporting truck of the character described, comprising front and rear pivot supports, a pair of differential wheel connecting mechanisms arranged in tandem relation and pivotally connected at their forward ends to the supports for up and down swinging movements at their rear ends, separate wheel pairs supporting the rear ends of said mechanisms and connected thereby for interdependent up and down differential movements, and a link member connected between the differential mechanisms to translate up movement of either wheel pair to down movements of the other, the said link member being connected at its forward end above the front support and at its rear end below the rear support.

4 23. A vehicle supporting truck of the character described, ,comprising a pair of differential wheel connecting mechanisms arranged Ain tandem relation and each swingablyfconnecte'd at its forward end to the vehicle for up. anddown.. swinging movements at its rear end. separa-tel wheel pairs supporting. the rearrends'n-of said mechanisms and connected thereby f-or interde,

pendent up and down differential movements. :an arm extending from one of the differential mechanisms, .a member connecting saidv arm to the other differential mechanism and movable endwise by up and down movements of'cither i.

wheel pair to oppositely move the other wheel pair, and means separate from saidconnectng member for yieldably resisting lupward movements of the wheels.

24. A vehicle supporting truck of the character described, comprising a pair of differential-wheel connecting mechanisms arranged in tandemrelai-- tion and each swingably connected at-its forward i end to the vehicle for up and down swinging movements at its rear end, separatewheel pairs supporting the rear ends of said mechanisms and connected thereby for interdependent lup and` down differential movements, arms,` ,extendingl from the differential mechanisms, a member.v connecting said arms and movable endwise byup A and. down movements of either wheel pair to,

oppositely move the other wheel pair, means forming part of said connecting memberfor yieldably resisting upward movements of the Wheels, and means also forming partei/,the `said connecting member for adjusting its lengthto thereby adjust the wheels simultaneously.

25. In a vehicle supporting mechanism, the

:combination comprising a transverse pivot attached to the vehicle, a member having wide.

spread bearings at its forward end pivoted on said pivot member whereby the rear end of the member may swing upwardly and downwardly withr respect to the vehicle, a cranked axle journaled.=

at its forward end in each side of the member and extending rearwardly therealongside, ground wheels journaled on and supportingthe rear ends of they axles, means on the member differentially connecting the axles, and spring meansv operatively arranged to yieldably resist upward movements of the rear end of the member.

26. In a vehicle supporting mechanism, i the combination comprising a transversepivot member attached to the vehicle. a housing` having wide spread bearings at its forward end pivotedz on said pivot member whereby` the ,rearl end of the housing may swing upwardly and downwardly with respect to the vehicle, a cranked axle journaled at its-forward end in each side ofthe housing and extending rearwardly therealongside, ground wheels journaled on and supporting 1 the rear ends of the axles, means contained in the housing differentially connecting the axles, spring means operatively arranged to yieldably resist upward movements of the rearend of the housing, and the said wheels being mounted by the axles with one wheel offset forwardly of, the other.

2'7. In a vehicle supporting mechanism of "the character described, front and rear mounting brackets on the vehicle, front and rear tubes mounted in the' brackets and extending crosswise of the vehicle, a differential housing pivotallymounted at its forward" end adjacent the ends of both front and rear tubes and extending rearl wardly therefrom, wheel `supported cranked :axles journaled to each side of the housings,l means in .1 each housing differentially connectingthe axles; to Vtranslate up movements of either; toV down.,

2l ment of either to downward movement of the other, spring means acting between the Vehicle and rear end portions of the housing member to yieldably resist upward movement of the latter,`

there being two of such `assemblies in tandem at each side of the vehiclefand said spring means comprising a forwardly and rearwardly extending leaf spring connected at its opposite ends to the housing member, and a member secured to the center of the leaf spring andhaving a bearing journaled on the pivot member between the lugs of the rear bracket to produce a walking beam action between the front and rear wheel assemblies.

ADOLPI-I RONNING.

REFERENCES CITEDl The following references are of record in the file of this patent:

Number 25 Number Name Date Marcum Dec. 26, 1933 Fageol Nov, 20, 1934' Kendall June 1, 1937 Dodge June 28, 1938 Peterman Sept. 5, 1939 Ash Mar. 19, 1940 Peterman Mar. 19, 1940 Ronning July 23,1940 Larison July 30, 1940 Ronning Oct. 15, 1940 Larison Dec. 24, 1940 Peterman Apr. 1, 1941 Running Apr. 1, 1941 Judd Apr. 29, 1941 Price Jan. 13, 1942 Ronk Dec. 1, 1942 Harbers Apr. 25, 1944 Larison May 23, 1944 Sullivan Oct. 16, 1945 Pearson Feb. 26, 1946 Larison Dec. 3, 1946 FOREIGN PATENTS Country Date Germany Oct. 23, 1928 France May 17, 1924 Germany Dec. 20, 1927 

